Moistening apparatus



Nov. 7, 1944. J. 0. R088 MOISTENING APPARATUS Filed Jan. 12, 1943INVENTOR I AT ORNEY Patented Nov. 7, 1944 UNITED STATES PATENT OFFICEMOISTENING APPARATUS John 0. Ross, New York, N. Y., assignor to J. 0.Ross Engineering Corporation, New York, N. Y., a corporation of New YorkApplication January 12, 1943, Serial No. 472,176

4 Claims.

This invention relates to increasing the moisture content oiwater-absorbent material. A specific embodiment of the inventionpertains increasing the water content of a strip of fabric of lowtensile strength.

An object of this invention is an apparatus for providing a low tensilestrip of water-absorbent material with a predetermined moisture contentuniformly distributed throughout the material in the shortest possibletime and while the material is kept free from tension.

According to this invention, moisture is added to the strip bycontinuously feeding it into and out of a chamber in which it iscontacted with hot humid air and maintaining the stripbefore and afterpassage through said chamber at a temperature below the temperature ofthe contacting air. For example, by impinging the strip with aconditioned air stream of 95 F. temperature and 90% relative humidity,the strip being of approximately 75 F. temperature, a surface deposit isformed on the strip in the matter of a very few seconds and thetemperature of the strip is brought up very close to the dew pointtemperature of the air. From then on, moisture can be absorbed into thestrip only by the slow process of approaching equilibrium. The moistureprovided by the surface deposit usually is less than is required to givethe strip the desired moisture content. Therefore, to supply the desiredmoisture content to the strip, the strip, after being subjected to thetreatment above described, is cooled to approximately its originaltemperature under conditions such as to prevent appreciable evaporationof the deposited moisture and then the above-described treatment withhot humid air is repeated. Preferably, the strip is. cooled by impingingwith cold air of high humidity b t may be cooled by other suitablemeans. The strip is subjected to repeated cycles of the treatment abovedescribed until it reaches the desired moisture content. Each treatmentof the cooled strip with hot humid air is eflected in a short periodwhile each cooling operation likewise requ res only a short period sothat in the matter of a few seconds the strip is brought to the des redmoisture content as only a relatively few passe"- of the strip throughthe hot humid air is required to provide it with the desired moisturecontent. In order to support the strip free from tensi n during themoistening operation, a succession of conveyors is provided forsupporting the strip during its subjection successively to the hot hum datmosphere and cooling it between such treatany tensile strain duringthe addition of moisture I thereto.

Other objects, novel features and advantages of this invention willbecome apparent from the following specification and accompanyingdrawing, wherein the single figure of drawing illustrates schematicallyone form of apparatus for treating strip material according to theinvention.

The treating chamber I0 is divided into a cooling compartment II and amoistening compartment l2. In each compartment are provided severalrolls l3 on which are supported conveyors H, each of which is arrangedpartly in compartment H and partly in compartment l2. The partition l5which divides the chamber I 0 into the compartments II and I2 isprovided with apertures it through which the conveyors pass. Drive meansI l. are provided for rotating the rollers I 3 to cause feeding of theconveyors M.

In the cooling chamber l l is provided a plurality of ducts l8 eachoverlying the top reach of one conveyor. In the moistening chamber 12 isprovided a plurality of ducts l 9 each arranged above the upper reach ofa conveyor. Both the ducts l8 and iii are supplied with a large numberof relatively small apertures through which air may be discharged towardthe underlying conveyor. A supply duct 20 is provided for deliveringcold humid air to the ducts l8 and a suppl duct 2| is provided fordelivering hot humid air to the ducts l9.

of the top conveyor and is advanced successively by the top conveyor andthe remaining conveyors alternately through the compartments II and I2and is finally discharged from the bottom conveyor through the aperture26 in the wall of compartment i I. The strip S thus passes at apredetermined rate back and forth in several reaches through the twocompartments and after its last passage through the cooling compartmentis discharged from the treating apparatus to suitable take-up mechanism,not shown. From the duct 20 cold moist air 01' a predeterminedtemperature is supplied to the ducts i8 and through the duct 2| heatedair of predetermined air and moisture content is supplied to the ductsIS. The air thus supplied is caused to impinge on both sides of thestrip as it travels through the apparatus.

In normal operation of the apparatus, the strip S is first brought to apredetermined temperature in the compartment H, for example, 75 F. andthen is carried into the compartment 12 where it is subjected to airpreferably of 95 F. and 90% relative humidity. The strip is thenreturned to the cooling chamber where its temperature is reduced and thecycle above described is repeated a predetermined number of times.

During its various passes through the moistening chamber, a surface filmof moisture is deposited on the strip due to the fact that itstemperature is below the dew point temperature of the air supplied tothe ducts l9 and the temperature of the strip is brought up very closeto the dew point temperature of the air. After the temperature of thestrip has nearly reached the dew point temperature of the air no furthermoisture will be deposited on the strip except by the slow process ofapproaching equilibrium. The deposit of the surface film and theelevation of the strip temperature to nearly the dew point temperatureof the air takes place in a matter of a few seconds and the strip speedand the length of its path in the compartment I2 is so determined thatit remains in the compartment only long enough for such effects to beaccomplished. The strip absorbs the deposited moisture and is thenreturned to the compartment II for cooling and appreciable evaporationof moisture from the strip is prevented by the humid condition of thecooling air. Through successive treatments, the strip absorbs enoughincrements of moisture to provide it with the desired moisture contentin comparatively short time as the alternate passages of the stripthrough the cooling chamber 2. Apparatus for moistening a continuouslymoving strip oi water-absorbent material comprising a horizontallyelongated housing divided by a vertical wall into a pair of chambers, aplurality of superposed conveyors each common to both chambers andpassing through restricted openings in said vertical wall, a first and asecond opening in vertically spaced planes in an outer side wall of oneof said chambers, the first of said openings being provided for thepassage of said strip from the exterior of said housing to the first ofsaid conveyors and the second of said openings being provided forwithdrawing it from the last of said conveyors to the exterior of saidhousing, means for driving successive conveyors in opposit directions,the delivery end of each conveyor except the last one being sopositioned as to discharge said strip to the next conveyor, ducts ineach chamber arranged above the conveyors, each of said ducts havingapertures adapted to direct air toward said strip on the underlyingconveyor, means for supplying cold humid air to the ducts in onechamber, and means for supplying hot humid air to the ducts in theremaining chamber.

3. Apparatus for moistening a continuously moving strip ofwater-absorbent material comprising a horizontally elongated housingdivided by a vertical wall into a pair of chambers, a plurality ofsuperposed conveyors each common to both chambers and passing throughrestricted openings in said vertical wall, a pair of openings invertically spaced planes in an outer side wall of one of said chambers,the upper of said openings being provided for the passage of said stripfrom the exterior of said housing to the upper of said conveyors and thelower of said openings being provided for withdrawing it from the lowerof said conveyors to the exterior of said housing, means for drivingsuccessive conveyors in opposite directions, the delivery end of eachconveyor onds each.

It is of course understood that various modifications may be made in theapparatus and procedure above described without in any way departingfrom the spirit of the invention as defined in the appended claims.

I claim:

1. Apparatus for moistening a continuously moving strip ofwater-absorbent material comprising a horizontally elongated housingdivided by a vertical wall into a pair of chambers, a plurality ofsuperposed conveyors each common to both chambers and passing throughrestricted openings in said vertical wall, a first and a second openingin vertically spaced planes in an outer side wall of one of saidchambers, the first of said openings being provided for the passage ofsaid strip from the exterior of said housing to the first of saidconveyors and the second of said openings being provided for withdrawingit from the last of said conveyors to the exterior of said housing,means for driving successive conveyors in opposite directions, thedelivery end of each conveyor except the last one being so positioned asto discharge said strip to the next conveyor, means for supplyingcoldhumid air to said strip in one chamber and means for supplying hot humidair to said strip in the remaining chamber.

except the lower one being so positioned as to discharge said strip tothe next lower conveyor, means for supplying cold humid air to saidstrip in one chamber, and means for supplying hot humid air to saidstrip in the remaining chamher.

4. Apparatus for moistening a continuously moving strip ofwater-absorbent material comprising a horizontally elongated housingdivided by a vertical wall into a pair of chambers, a plurality ofsuperposed conveyors each common to both chambers and passing throughrestricted openings in said vertical wall, a pair of openings invertically spaced planes in an outer side wall of one of said chambers,the upper of said openings being provided for the passage of said stripfrom the exterior of said housing to th upper of said conveyors and thelower of said openings being provided for withdrawing it fromthe lowerof said conveyors to the exterior of said housing, means for drivingsuccessive conveyors in opposite directions, the delivery end of eachconveyor except the lower one being so positioned as to discharge saidstrip to the next lower conveyor, ducts in each chamber arranged abovethe conveyors, each of said ducts having apertures adapted to direct airtowards said strip on the underlying conveyor, means for supplying coldhumid air to the ducts in one chamber, and means for supplying hot humidair to the ducts in the remaining chamber.

JOHN O. ROSS.

